Suspension system



June 23, 1970 G. A. KENDALL SUSPENSION SYSTEM 3 Sheets-Sheet 1 Filed April 21, 1967 INVENTOR.

June 23, 1970 G. A. KENDALL 3,516,628

SUSPENS ION SYSTEM G. A. KENDALL SUSPENSION SYSTEM June 23, 1970 v 3 Sheets-Sheet 5 Filed April 21, 1967 United States Patent O U.S. Cl. 248-18 11 Claims ABSTRACT F THE DISCLOSURE A stabilizing support system having a support surface connected to a telescoping support member, a liquid spring assembly which slides within the support member, at least three suspension levers, whose inner ends are pivotally connected to the telescoping support member and whose outer ends are connected to cables, support arm assemblies whose outer ends are pivotally connected to intermediate points of the suspension levers and whose inner ends are pivotally connected to the lower portion of the liquid spring assembly. The lengths of the telescoping support members can -be varied by actuating means to change the position of the support surface which is resiliently supported by the suspension levers acting through the liquid spring assembly.

This invention relates to a stabilizing suspension system. More speciiically, the invention pertains to a stabilizing suspension system which has particular suitability in supporting a missile.

In order to protect a missile and keep it in a state of readiness for use at any time, the missile may be stored in an underground silo. Within the silo, the missile is stored in an upright position resting on a missile support platform. The functioning of the missile support platform is quite critical to the success of the missile itself since the platform must support the missile in a precise location and protect the missile from ground shock, such as would be caused by the explosion of a bomb adjacent the underground silo.

Due to its great height, a missile in an upright position is quite vulnerable to roll forces which would produce a tipping action on the missile platform. Even a minor tipping at the base of the missile produces a major tipping at the top Of the missile, which may be fifty feet or more above the missile base. This can result in the missile tipping over within vthe silo such that it rests in part against the silo wall. The outer skin of a missile is very thin so that the missile is quite susceptible to damage. Thus, the tipping over of a missile within its concrete silo can damage it so that it is completely unsuitable for further service. Moreover, as will be appreciated, the removal of a missile from a silo after it has tipped over is no easy task since the cramped spacing within the silo makes it very difficult to maneuver the missile into an upright position so vthat it can be removed.

In addition to precisely positioning the missile within the concrete silo and protecting the missile from ground shocks, a missile platform should be somewhat flexible so as to be capable of accommodating missiles of various weights. In the long term development of a missile system, it is not uncommon that a first generation missile will be made obsolescent by a second generation missile, which in turn is made obsolescent by a third generation missile, etc. The state of the art changes very rapidly in the missile eld and, as new missiles are developed, old missiles are removed from their underground silos and replaced with more advanced missiles. The replacement of one missile with another can be quite costly. If the missile support platform is inflexible in design,

3,516,628 Patented June Z3, 1970 ICC it can only support one particular type of missile. Under these circumstances, the replacement of one missile with a more advanced missile requires replacement of the entire missile support platform with a new platform designed specifically for the newer missile.

In addition to the above requirements for a missile support platform, such a platform should be capable of easy adjustment after the missile has been installed within the silo. Although missile silos: are normally kept at a constant temperature, a breakdown in the air conditioning system can result in a sharp temperature fluctuation lwithin the missile silo. This, in turn, can result in expansion or contraction of the various metal parts in the metal support platform, which, in turn, can produce a change in the positioning of the support platform and the missile. Since the missile must be kept in a state of constant readiness, it is desirable that the missile support platform be capable of adjustment in the positioning of the platform `to keep the missile in the desired location irrespective of temperature fluctuations within the silo.

Similarly, the missile support platform may be deformed slightly due to extreme shock loading such that 'the position of the platform is slightly changed. In such instances, it is very desirable that the support platform be capable of being repositoned to return the missile to its required location within the silo.

Still another requirement for a missile support platform is that it have a reserve capability such that failure of one critical component of the support platform will not destroy the missiles capability. For example, if the missile support platform contains a spring, it is desirable that the lplatform have a reserve capability of maintaining the missile at a precise position ywithin the silo, even though the spring should fail.

Missile support systems which are presently available are not generally satisfactory. Although they may possess some of the above enumerated capabilities, they do not possess all of them as required for a successful and reliable support system. Further, missile support systems which are presently in use or have been proposed ofttimes tend to be very complex in structure. As will be appreciated, as the complexity of such a system is increased, its reliability is decreased. Thus, in addition to the above requirements for a missile support system, a further requirement is that it be relatively simple in structure so that it will have a high reliability.

In solving the problems of the prior art, I have provided a missile support platform which includes within its structure a telescoping upper member adapted to present a supporting member in engagement with the missile base, which telescoping upper member ts in telescoping relation with a telescoping lower member. A liquid spring is positioned between the telescoping upper and lower members and holds the members in a resiliently spacedapart relationship. Positioned about the exterior of the telescoping lower member are at least three suspension levers each of whose outer ends are adapted to engage a vertical support means such as a cable having its upper end anchored in the wall of the missile silo and its lower end attached to the outer end of a suspension lever.

The inner ends of each of the suspension levers are pivotally connected to the telescoping upper member. Spaced uniformly about the exterior of the telescoping lower member are at least three support arms. The spacing of the support arms corresponds generally with the spacing of the suspension levers. 'lhe inner ends of the support arms are pivotally connected to the telescoping lower member adjacent its lower extremity. The outer ends of the support arms are pivotally connected to the suspension levers with the pivotal connections thereto being spaced intermediate the outer and inner ends of the suspension levers.

Additionally, the missile support platform of my invention is provided With actuating means which are adapted to change the position of the missile support platform so as to raise it, lower it, or tilt it slightly in any direction. The actuating means conveniently includes a plurality of motors, each of which is operably connected to a support arm and is adapted to change the length of the support arm. By changing the length of one or more of the support arms, the position of the supporting surface on which the missile rests can be made to undergo an infinite number of positions.

A specific embodiment of the invention is illustrated in the accompanying drawings in which like reference characters designate like parts of the several views thereof, wherein:

FIG. 1 is a perspective elevational view of the missile support platform;

FIG. 2 is a partial top view of the missile support platform with portions of the structure being broken away for ease of illustration;

FIG. 3 is a front-sectional view of the missile support platform along the line 3-3 of FIG. 2;

FIG. 4 is a diagrammatic partial front sectional view showing the missile support platform undergoing an extreme downward excursion;

FIG. 5 is a diagrammatic partial front sectional view showing the missile support platform undergoing an extreme upward excursion; and

FIG. 6 is a diagrammatic partial front-sectional View illustrating the repositioning of the lmissile platform after failure of the liquid spring.

As shown in FIG. 1, the missile 2 rests on a support ring 4 having an open center portion 78. Spaced uniformly at 120 intervals about the bottom of support ring 4 are support brackets 18. Links 16 are pin connected at their outer ends to brackets 18 and are pin connected at their inner ends to support brackets 14 which are positioned at corresponding 120 intervals about the exterior surface of a telescoping support member 8 which is centrally positioned with respect to the open center portion 78. Extending downwardly and inwardly from support brackets 18 are tripod links 20 which are pin connected at their outer ends to support brackets 18.

The inner ends of tripod links 20 are pin connected to support brackets 22 located at corresponding 120 intervals about a thickened lower shoulder 12 of telescoping support member 8. The support brackets 14 positioned exteriorly about the upper portion of telescoping support member 8 are lixed to an upper shoulder portion 10 of telescoping support member 8. The support ring 4, links 16, telescoping support member 8, and tripod links 20 are joined together to form a rigid structure with the telescoping support member 8 being located at the center of the opening 78 in the support ring 4. This creates a rigid, yet open structure, through which the exhaust from the missile passes when it is fired.

Positioned at corresponding 120 intervals about the exterior lower surface of telescoping support member 8 are end pivot brackets 26. Suspension levers 24 are pin connected at their inner ends to the end pivot brackets 26. Connected to the outer ends of suspension levers 24 are cable connectors 44 which, in turn, are connected to cables 6. A liquid spring assembly 36 is positioned in telescoping relation Within the interior of telescoping support member 8. Positioned at corresponding 120 intervals about lower exterior shoulder 34 are lower pivot brackets 32. The lower and inner ends of support arm assemblies 30 are pin connected to the lower pivot brackets 32. The support arm assemblies 30 are pin connected near their upper and outer extremities to center pivots 28 which may be made integral with suspension levers 24 and located at an intermediate point between the inner and outer extremities of suspension levers 24.

As shown in FIG. 2,r links 16 have a generally Y- 4 type shaped transverse configuration. The inner ends of links 16 form a pair of clevises 38 which are attached to support brackets 14 by means of pins 40. The outer ends of links 16 form clevises 39 which are connected by pins 41 to support brackets 18.

Tripod links 20 are connected to support brackets 22 by means of pins 42. Suspension levers 24 form a clevis 45 at their outer ends 'which retains a cable connector 44 by means of a pin 46.

Turning to FIG. 3, the internal mechanism of liquid spring assembly 36 comprises a cylinder 48 which moves in telescoping relation within the cavity 54 within the interior of telescoping support member 8. Cylinder 48 is lled with a compressible fluid 70, such as a silicone uid. Extending centrally into cylinder 48 through a high pressure sliding seal 58 is a piston rod 52. Resting against the top surface of piston rod 52 is a downwardly extending boss 56 formed by the inner top surface of telescoping support member 8. The seal 58 is held in place by means of a seal closure member 60 which is threadedly engaged with cylinder 48.

A piston 50 is attached to the piston rod 52 at its lower end and slides within cylinder 48 in contact with a cylindrical baffle 62 having openings 64 therein. The cylinder 48 is held in rm telescoping engagement with telescoping support member 8 by means of bearings 68 and 66. Upper bearing 68 extends circumferentially about the outer surface of cylinder 48 and is held in place in a groove 69 therein in contact with telescoping support member 8. Lower bearing 66 is held in place by means of an annular bearing support bracket 81 and a plurality of bearing support pins 80.

Support ring 4 has an upstanding lip 76 within which rests the missile 2 on supporting surface 79. Support arm assembly 30 includes an actuating means 74 which may, for example, be an electric motor, hydraulic motor, or the like. Actuating means 74 engages a screw thread 75 formed on the exterior of arm 72. On the actuation of actuating means 74 to engage with and move with respect to screw thread 75, the length of support arm assembly 30 between lower pivot bracket 32 and center pivot 28 can be either lengthened or shortened. -On shortening of the distance between the center pivot 28` and the support bracket 32 shown in FIG. 3, the liquid spring assembly 36, telescoping support member 8 and the support ring 4 are tilted in a direction opposite from the illustrated lower pivot bracket 32. Likewise, on lengthening of the distance between lower pivot bracket 32 and center pivot 28 by means of actuating means 74 the liquid spring assembly 36, telescoping support member 8 and the support ring 4 are tilted in the direction of lower pivot bracket 32 shown in FIG. 3. Since there are three support arm assemblies 30 positioned at 120 intervals about liquid spring assembly 36, each of which can be lengthened or shortened, the position of support ring 4 maybe varied, either up or down by shortening or lengthening all of the support arm assemblies, or tilted at any angle by shortening or lengthening one of the support arm assemblies 30 with respect to the others, etc.

In its loaded position with the missile 2 resting on support ring 4, the piston 50 occupies a rest position as generally shown in FIG. 3. Liquid springs are known to the art and function through use of a confined compressible liuid which exerts a reactive force on a piston extending into the fluid. As shown in FIG. 3, the bottom surface of piston 50 has a larger surface area than the upper surface of said piston, the center portion of which is afxed to piston rod 52. By virtue of this difference in the surface areas, which is equivalent to the diameter of piston rod 52, the-compressible fluid 70'exerts a greater force on the bottom surface of piston 50 which force is transmitted through piston rod.52 and boss 56 into the telescoping sppport member 8 and from thence to the support ring 4 to support the vmissile 2. On downward movement of piston 50 and pistonfrod S2. into cylinder `48, the volume within cylinder 48 is reduced due to the increased volume occupied by the entry of piston rod 52. This further compresses the fluid 70 which thus exerts a greater force against the bottom surface of piston 50 thereby tending to return the piston 50 to its loaded rest position, as shown in FIG. 3. On movement of the piston 50 and piston rod 52, either up or down within the cylinder 48, compressible fluid 70 is forced through the holes 64 in cylindrical bale 62. The passage of fluid 70 through holes 64 exerts a damping action on the liquid spring, thereby reducing the oscillations of the piston rod 524 and piston 50 within cylinder 48.

The fluid 70 undergoes a pressure drop on passage through holes 64. Thus, under dynamic loading, there is a pressure differential between the top and bottom surfaces of the piston 50. On downward movement of piston 50, fluid 70 flows from the region below the piston to the region above the piston by passing through the holes 64 in cylindrical bafe 62. The resulting pressure in the region above the piston is less than that in the region below the piston. On upward movement of piston 50 within cylinder 48, the uid 70 flows to the region below the piston with the result that the pressure in this region is less than that above the piston.

The effect of an earth shock resulting in a downward force on the support ring 4 is illustrated diagrammatically in FIG. 4. As shown, the telescoping support member 8, piston rod 52, piston 50, and support ring 4, all move downwardly with respect to the cylinder 48. The position of the cables 6 remains relatively fixed as does the point of attachment of the cables 6 to the suspension levers 24. The suspension levers 24 pivot about end pivot brackets 26 and thereby are inclined upwardly as a result of the downward excursion of the support ring 4. While in this position, the compressible fluid 70 is compressed to a greater extent due to the entry of the piston rod 52 within cylinder 48, thereby reducing its volume. This exerts a greater reactive upward force against the bottom face of the piston 50 tending to return it to its normal rest position, as shown in FIG. 3.

As shown in FIG. 4, the seal '58 shown in FIG. 3, is composed of an upper seal plate 82, a lower seal plate 86, and a resilient seal member 84 positioned therebetween. As the pressure within cylinder 48 is increased due to the downward excursion of the piston rod 52 within cylinder 48, the compressible fluid 70 exerts a greater force on the bottom surface of the lower seal plate 86. This in turn places a greater compressive force on the resilient seal member 84, thereby urging it into closer contact with the piston rod `52. In this manner, the seal automatically adjusts to increasing pressure within the cylinder 48.

The effect of a ground shock causing an upward force on the support ring 4 is illustrated diagrammatically in FIG. 5. As illustrated, support ring 4, telescoping support member 8, piston rod 52, and piston 50 have all moved upwardly with respect to the cylinder 48 which moves in a telescoping manner within telescoping support member 8. As a result, the pressure within cylinder 48 is reduced and the fluid 70 is allowed to expand. The position of the cables 6 and their points of connection to suspension levers 24 remains relatively fixed and the suspension levers 24 therefore pivot downwardly about their connections to end pivot brackets-26. Due to the decreased pressure within cylinder 48, the piston 50 is urged downwardly by the weight of the ring support 4 and the missile 2 supported thereon. This tends to return the piston S to its normal rest position, as shown in FIG. 3.

The functioning of actuating means 74 in the event of failure of the liquid spring is illustrated diagrammatically in FIG. 6. On failure of the liquid spring, such as, for example, by a leak allowing the escape of the compressible fluid 70. the piston rod '52 and piston 50 move downwardly within cylinder 48 until the boss 56 is in contact with seal closure member 60. The cables 6, not

shown in this View, remain relatively xed, as do their points of attachment to suspension levers 24. The support levers 24, center pivots 28, actuating means 74, and the end pivot brackets 26 occupy the positions shown in solid line in FIG. 6 when the liquid spring has failed. The position of the links 16 and tripod links 20 during this occurrence are likewise shown in solid line drawing in FIG. 6.

In order to raise the missile back to its original position, each of the actuating means 74 is actuated to move it along screw thread 7'5 to a new position 74' shown in phantom in FIG. 6. This moves the center pivot to a new position 28', shown in phantom, thereby rotating suspension levers 24 to a new position 24. As a result, the end pivot brackets 26 move upwardly to a new position 26', tripod links 20 and support brackets 22 move upwardly to new positions 20 and 22', boss 56 is moved upwardly to a new position shown at 56', and links 16 are moved to a new position shown at 16. The net result is that the entire missile support platform is moved upwardly as a solid unit due to the movement of actuating means 74 along the screw threads 75 to shorten the distance between each of the lower pivot brackets 32 and center pivots 28.

As described, my missile support platform provides a support system having a low spring rate in vertical translation due to the effect of the liquid spring. The missile support platform acts as -a pendulum when subjected to a transverse force, due to the length of the cables 6 which are anchored at their upper ends in the wall of the missile silo. Thus, a transverse force moves the missile support platform freely from side to side while maintaining the missile in an essentially vertical positiono My missile support platform has a very high resistance to roll, that is to a tipping force `which would tend to tilt the plane of the supporting surface 79. Resistance to roll is afforded by the strength and elasticity of the cables 6. The cables are generally designed to have a spring rate in the order of ten or more times the spring rate of the liquid spring. Thus, when subjected to a ground shock which imposes a tilting force on the support ring 4, the natural tendency of the system is to absorb the tilting force by means of a downward or upward excursion as illustrated in FIGS. 4 and 5.

As shown in FIG. 3, an unbalanced force exerted on one of the suspension levers 24 will be resisted by a force couple through lower bearing 66, upper bearing 68 and from thence to the telescoping support member 8. The relatively large distance between lower bearing 66 and upper bearing 68, as compared with the vertical distance between lower bearing 66 and lower pivot brackets 32 insures that the magnitude of the forces in the resisting force couple will be of a sufficiently low magnitude to be readily absorbed by telescoping support member 8.

As described, my invention provides an extremely flexible missile support platform which can accommodate missiles of various sizes by increasing or decreasing the pressure of the compressible uid within the liquid spring. Also, my missile support platform can be adjusted to change the position of the missile in situ when in place within a missile silo and provides a low spring rate in vertical translation and in transverse translation, and a very high resistance to roll forces which would tend to tilt the missile about its lower surface which rests on a supporting ring within the silo.

As described herein, my suspension system has particular suitability for supporting a missile. However, my suspension system can be used for other applications, such as supporting an underground structure which houses equipment that must be insulated from ground shocks.

It should be understood that the specific embodiment of my invention is described only for purposes of illustrating my invention. Numerous variations of my invention will be apparent to those skilled in the art on reading the foregoing description.

I claim:

1. A support platform comprising: a support stand including a telescoping upper member; a. telescoping lower member positioned in telescoping relation within said telescoping upper member; a liquid spring placed between said telescoping upper and lower members and adapted to hold said members in a resiliently spaced-apart relation; at least three suspension levers generally uniformly spaced about the exterior of said telescoping upper member, the inner ends of said suspension levers being pivotally connected to said telescoping upper member; at least three support arms uniformly spaced about the exterior of said telescoping lower member; the spacingV of said support arms corresponding generally lwith the spacing of said suspension levers; the inner ends of said support arms being pivotally connected to said telescoping lower member adjacent its lower extremity; the outer ends of said support arms being pivotally connected to intermediate points of said suspension levers spaced outwardly from said inner ends, the outer ends of said suspension levers adapted to engage a vertical support means.

2. The support platform of claim 1 including actuating means adapted to change the positioning of said support stand.

3. The support platform of claim 2 wherein said actuating means includes a plurality of motors, each of said motors being operably connected to each of said support arms and adapted to change the length of said support arms.

4. The support platform of claim 1 including vertical support means adapted to support the outer ends of said suspension levers.

5. The support platform of claim 4 wherein said vertical support means includes a plurality of suspension cables, each of said cables connected at its lower end to the outer end of a suspension lever.

46. The support platform of claim 1 wherein said telescoping upper and lower 'members are supported in sliding relationship by an upper and a lower bearing positioned between said telescoping upper and lower members, the vertical spacing between said upper and lower bearing being sufficiently large to reduce the magnitude of forces imparted to said telescoping upper member by an imbalanced force applied through one of said suspension levers.

7. The support platform of claim 1 wherein said support stand includes a support ring having an open center portion, and a plurality of connecting links fixedly positioning said telescoping member at the center of said open portion and connecting said telescoping upper member to said support ring.

8. The support platform of claim 1 wherein said liquid spring includes damping means.

9. A support platform comprising: a support stand including a telescoping upper member; a telescoping lower member positioned in telescoping relation within said telescoping upper member; a spring placed between said telescoping upper and lower members and adapted to hold said members in a resiliently spaced-apart relation; at least three suspension levers generally uniformly spaced about the exterior of said telescoping upper member, the inner ends of said suspension levers being pivotally connected to said telescoping upper member; at least three support arms uniformly spaced about the'exterior of said telescoping lower member, the spacing of said support arms corresponding generally with the spacing of said suspension levers; the inner ends of said support arms being pivotally connected to said telescoping lower member adjacent its lower extremity; the outer ends of said support arms being pivotally connected to intermediate points of said suspension levers spaced outwardly from said inner ends, the outer ends of said suspension levers adapted to engage a vertical support means.

10. The support platform of claim 9 including damping means for said spring.

11. A support platform comprising: a support member having an upper and a lower surface; a spring means having a xed element and a movable element resiliently biased away from said xed element, said xed element being connected to the lower surface of said support member; at least three suspension levers, each of said suspension levers being pivotally connected at its inner end to said fixed element, and means connecting each of said suspension levers from a point intermediate its end to said movable element.

References Cited UNITED STATES PATENTS 3,208,707 9/1965" Blumrich 267-1 3,224,751 1'2/ 1965 Andrews 267-1 3,266,373 8/1966 Brown 89-1.81 X 3,289,533 12/1966 Brown 89-l.81

ROY D. FRAZIER, Primary Examiner I. F. FOSS, Assistant Examiner U.S. Cl. X.R. 

